Calculating an Empirical Formula Ascorbic acid (vitamin C) contains 40.92% C, 4.58% H, and 54.50% 0 by mass. What is the empirical formula of ascorbic acid? A 2.144-g sample of phosgene, a compound used as a chemical warfare agent during World War I, contains 0.260 g of carbon, 0.347 g of oxygen, and 1.537 g of chlorine. What is the empirical formula of this substance? (a) CO2CI6 (b) COCI2 (c) CO.022O0.022CI0.044 (d) C2OCI2

Solution 1PE Step 1 Empirical formula :Empirical formula" is a REAL IMPORTANT concept. Here's the definition: the formula of a compound expressed as the smallest possible whole-number ratio of subscripts of the elements in the formula For example, CH CO3 has two carbons, four hydrogens and two oxygens. So we could write the formula like this: C H O and so it reduces to CH O. 2 4 2 2 below describes the steps involved in calculating an empirical formula. the method for converting percentage composition to an empirical formula. Percent to mass. Mass to mole. Divide by small. Multiply 'til whole. Step 2 Per cent to mass: Ascorbic acid (vitamin C) contains 40.92% C, 4.58% H, and 54.50% 0 by mass. Carbon =40.92%.=40.92g Hydrogen =4.58%=4.58g Oxygen =54.50%=54.50g. Step 3 Mass to mole : Carbon =40.92 g of C*1 mol of C/12.2g of C=3.35moles. Hydrogen =4.58 g of H*1 mol of H/1.008 g of H=4.54moles . Oxygen =54.50 of O*1 mol of O/16.0g of O=3.40 moles . Step4 Divide by small: Determine mole ratios by dividing the moles for each element by the smallest number of moles. C: 3.407mol/3.406mol=1.000 H: 4.54mol/3.406mol=1.33 H: 3.406mol/3.406mol=1.000